1. Field of the Invention
The present invention relates to plasma display panels which display color images using gas discharge, and particularly to a structure for surface-discharge ac plasma display panels which makes it possible to easily fabricate the plasma display panels and their front and back panels and to a method for manufacturing the plasma display panels.
2. Description of the Related Art
Surface-discharge ac plasma display panels have been put into practical use for large full-color flat display devices. These panels each have a front panel and a back panel with discharge gas filled therebetween. The front panel comprises a front substrate and pairs of display electrodes disposed on the front substrate along display lines of the front panel. The back panel comprises a back substrate and fluorescent phosphors superposed on the back substrate. A surface discharge from each pair of display electrodes generates vacuum ultraviolet light which causes the fluorescent phosphors to emit visual light, and thus color images can be displayed. In general, the display electrodes are covered with a dielectric layer formed of a low-melting-point glass, and black stripes are disposed between the pairs of display electrodes to increase the contrast ratio of displayed images. The back panel has address electrodes covered with a dielectric layer and extending under the fluorescent phosphors so as to cross the display electrodes. Barrier ribs (often referred to as barrier walls) for partitioning the discharges are also disposed so as to correspond to the address electrodes.
However, in the manufacturing process of the known plasma display panel, the electrodes, the dielectric layers, the barrier ribs, and other components must be formed and then fired separately, as shown in the flow charts of manufacturing processes in FIGS. 6 and 7. Therefore the front panel, which includes the display electrodes and the dielectric layer (having a two-layered structure) must be fired three times, and the back panel, which includes the address electrodes, the dielectric layer, and the barrier ribs must be fired four times. In the flow chart in FIG. 6, the dielectric layer of the front panel is composed of a lower layer and an upper layer. The lower layer is fired at a temperature around the softening point of the constituent thereof to prevent reaction with the display electrodes, and the upper layer is fired at a temperature 100° C. higher than the softening point of the constituent thereof so that the surface of the upper layer become smooth. The dielectric layer of the front panel can have a monolayer structure by selecting the material of the display electrodes. In this instance, the front panel is fired twice. As described above, the known plasma display panel having the front panel and the back panel requires a lot of firing steps. It takes 4 to 5 hours to perform each firing step and, thus, the entire manufacturing process is long. Also, such a large number of steps leads to a reduced manufacturing yield.